A classic book is probably the Microbe Hunters (1926), by de Kruif and
although is still in print, I don't believe it is available in a hard
cover. I was able to get a copy from an antiquarian book dealer.
We are in the process of publishing a book titled Microbe Hunters: Then
and Now, which pays tribute to the original work and has contributions by
more than 30 authors on various 'microbe' topics. The authors are quite
well known (Prusiner, Gallo, Fenner, Gershon, Beachy, Barbour, Koprowski,
Weller), but this help you because it is not yet published, let alone a
classic.
Ron Thompson
Medi-Ed Press